The Diamond series is engineered for one specific job: machining the sealing surface of ball valve balls where metal-to-metal tightness is required. The grinding cup accepts both abrasive stones and diamond inserts and is designed to process the widest possible range of ball sizes with the same tool holder, reducing setup time between batches.
All models are equipped with a SIEMENS 840D CNC and a RENISHAW probe for faster cup-to-ball centering. The sphere spindle is powered by a torque motor to ensure maximum torque at low rpm and is designed for machining roundness of 0.01 mm. A custom clamping system allows machining of all types of spheres, and the tailstock includes a CNC-controlled hydraulic compensation system for rigidity and precision during machining. High-capacity filtration, lubrication, and cooling systems support continuous production, and the machines are designed for quick installation on simple, cost-effective foundations.
Every machine is designed around the customer's production requirements. CMA Tec manufactures 100% of the mechanical parts in-house, completes assembly and testing in its own workshop, and installs the machine at the end user's facility with its own specialized technicians. An operator training course, including machining trials on sample parts, is part of the delivery process.
| Parameter | Unit | 4" | 16" | 24" | 40" | 64" |
|---|---|---|---|---|---|---|
| Z-X-X1 stroke | mm | 150x200x3 | 300x500x3 | 350x800x3 | 500x1300x3 | 800x2200x3 |
| Machining range | mm | Ø19-150 | Ø75-600 | Ø320-950 | Ø600-1500 | Ø1150-2400 |
| Sphere spindle size | mm | Ø100 | Ø200 | Ø400 | Ø600 | Ø600 |
| Max loading capacity | kg | 20 | 500 | 1,500 | 10,000 | 20,000 |
| Sphere spindle max speed | rpm | 200 | 100 | 80 | 80 | 80 |
| Grinding spindle speed | rpm | 2000 | 1000 | 200-1000 | 150-1000 | 50-500 |
| Spindle taper | size | ISO 40/ASA-4 | ASA-8 | ASA-11 | ASA-15 | ASA-15 |
| Spindle motor power | kW | 10 | 20 | 22.5 | 50 | 70 |
| Rapid speed (Z-X-X1) | m/min | 8 | 4 | 4 | 4 | 2 |
| Positioning accuracy | mm | ±0.005 | ±0.007 | ±0.007 | ±0.007 | ±0.007 |
| Installed power | kW | 20 | 60 | 70 | 90 | 200 |
| Machine weight | kg | 7,000 | 15,000 | 22,000 | 50,000 | 75,000 |
Specific sizes available on demand.
What ball sizes can the Diamond series machine? The five standard versions cover ball diameters from 19 mm to 2400 mm: 4" (Ø19-150 mm), 16" (Ø75-600 mm), 24" (Ø320-950 mm), 40" (Ø600-1500 mm), and 64" (Ø1150-2400 mm). Specific sizes are available on demand.
Can the Diamond grind hard-coated and CBN-coated balls? Yes. The series is designed for metal-seated balls coated with hard materials or CBN. The grinding cup accepts both abrasive stones and diamond inserts, and the questionnaire collects the coating type and hardness to match the right tooling.
What accuracy does the machine achieve? The sphere spindle is designed for machining roundness of 0.01 mm, with positioning accuracy of ±0.005 mm on the 4" version and ±0.007 mm on the larger sizes.
Which CNC does the machine use? All models are equipped with a SIEMENS 840D CNC and a RENISHAW probe for cup-to-ball centering.
Is installation and training included? CMA Tec assembles and tests each machine in its own workshop, then installs it at the end user's facility with specialized technicians. Delivery includes an operator training course with machining trials on sample parts.
CMA Tec Diamond is a series of CNC ball valve grinding machines for metal-seated balls, including hard-coated and CBN-coated balls, covering diameters from 19 mm to 2400 mm across five sizes (4", 16", 24", 40", 64"). Machines use SIEMENS 840D CNC, achieve 0.01 mm roundness, and are custom-built in Italy. In North America, Diamond machines are available through AV-TEK Consulting, which manages configuration, quoting, installation, and training coordination.
AV-TEK / Houston Office
4123 Hollister, Suite G
Houston, TX, 77080
AV-TEK / San Marcos Office
900 Barnes Dr. Suite 200
San Marcos, TX, 78666
